Polyamino alcohols and method for preparing them



Patented Apr. 24, 1951 POLYAMINO ALCOHOLS AND METHOD FOR A PREPARING THEM Murray Senkus, Terre Haute, Ind., assignor to Commercial Solvents Corporation, Terre Haute, Ind., a corporation of Maryland No Drawing. Application August 21, 1947,

1 Serial No. 769,986

7 Claims. (01. 260-563) This invention relates to new and useful polyamino alcohols and to a method for preparing same. More particularly, it relates to new compounds having the structural formula:

, I NH: CHs-N-CHr-OHzOH wherein R ,is ,cycloalkyl or alkyl substituted cycloalkylandR is preparing same.

As illustrative of some of the compounds coming within the, scope of the above formula there may be mentioned: 2-amino-2-methyl-4-cyclohexyl- 4 -[aza-1-pentanol, 2-amino-2-methy1-4- cyclopropyl-4-aza-1 pentanol, 2-amino-2-butyl- 4-methyl 4 cyclopentyl-4-aza l-pentanol, and the like.

The newpolyamino alcohols of my invention alkyl; I and to a method for may be prepared by catalytically hydrogenating 5-nitrotetrahydro-1,3,-oxazines in the liquid phase under pressure. Specifically, this process is effected by subjecting the aforesaid 5-nitrotetrahydro-1,3-oxa zines to hydrogenation at normal or elevated temperatures in the presence of a suitable hydrogenation catalyst and a solvent at a temperature which may vary from about 25 to not substantially in excess of 100 C. In general, any hydrogenation catalyst which is active within the aforesaid temperature range may be employed. For the majority of purposes, however, I have found it preferable to utilize Raney nickel. The hydrogenation reaction, in general, may be effected at hydrogen pressures ranging from about 500 pounds to about 3000 pounds pressure. I have found it preferable, however, to carry out such reactions at a pressure of approximately 1000 pounds per square inch and at temperatures of between 25 and 70 C. Suitable solvents which may be utilized in the reduction step are the lower aliphatic alcohols such as methanol, ethanol, and the like.

After the reaction is complete, as may be evi-. denced by the failure of additional hydrogen absorption, the catalyst is separated from the reaction mixture by filtration and the solvent is distilled off and the resulting p lyamino alcohol is recovered by rectification and further purified, if desired, by fractional distillation under high vacuum.

The 5-nitrotetrahydro-1,3-oxazines employed as starting materials for the production of the compounds of my invention are prepared by reacting equimolecular proportions of a suitable primary amine with a nitroparafiiin having the 2 nitro group attached to a primary carbon atom in the presence of formaldehyde, the latter being present in a molar ratio of about three to one of the nitroparafiin and one mole of the primary amine. A more detailed description of the methods by which such compounds can be obtained will be found in my co-pending application, U. S. Serial No. 650,134, filed February 25, 1946, now Patent No. 2,447,822.

My invention may be furtherillustrated by the following specific examples.

Example I Fifty-five grams 5-nitro-3-cyc1ohexyl-5-meth yltetrahydro-1,3-oxazine were hydrogenated in 500 ml. of methanol for two hours at C. and 1000 pounds per square inch in the presence of 10 g. of Raney nickel. Rectification of the reduced solution yielded 46 g. of 2-amino-2-- methyl 4-cyclohexyl 4-aza-l-pentanol, boiling at 98-101 0. at 0.1 mm.

Example II 2 amino 2 methyl-4-cyclopropyl-4-aza-1- pentanol was similarly prepared by hydrogenating 5 nitro-3-cyclopropyl-5-methyltetrahydro- 1,3-oxazine.

Example III Following the procedure described in Example I, 2-amino-2--butyl-4-methyl 4 cyclopentyl-laza-l-pentanol was prepared by hydrogenating 5 nitro 3 cyclopentyl-5-butyltetrahydro-1,3- oxazine.

Example IV Following the procedure described in Example I, 2-amino-2-methyl-4- (4-methylcyclohexyl) -4- aza-l-pentanol was obtained by hydrogenating 5 nitro-3-(4-methylcyclohexyl) -5 -methyltetra hydro-1,3-oxazine.

Example .V

Following the procedure described in Example I, 2-amino-2-ethyl-4-(2-ethylcyclohexyl) -4-azal-pentanol was produced by hydrogenating 5- ni tro-3 (l-ethylcyclohexyl) -5-ethyltetrahydro 1,3-oxazine.

The polyamino alcohols of my invention have been found to be useful in the preparation of numerous organic compounds. Other uses of these compounds will be apparent to those skilled in the art.

This application is a continuation-in-part of my Serial No. 650,135, filed February 25, 1946, now Patent No. 2,474,792.

My invention now having been described, what I claim is:

1. As new compositions of matter, polyamino alcohols having the following structural formula: 7

alcohols'having the followingstructural formula:

N112. cm- -ora-o-cmon wherein R is a member selected from the group consisting'of' cycloalkyl and'alkyl substituted cycloalkyl and R is-an'alkyl radical which comprises subjecting to catalytic hydrogenation, 5- nitrotetrahydro-1,31-oxazine having the following structural formula:

H: R-N' 0 H241 Hi 0 wherein. R. and R have their previously defined 5 significances', in the liquid phase, in the presence of a reduced nickel catalyst at elevated-pressure and elevated temperature.

6. A process for the preparation of polyamino alcohols having the following structural formula:

NH, CH NCH JJOH OH wherein R is a member selected from the group consisting of cycloalkyl and alkyl substituted cycloalkyl and R is an alkyl radical which comprises subjecting to catalytic hydrogenation, 5- nitrotetrahydro-1,3-oxazine having the following structural formula:

wherein R and R have their previously defined significances-,'in the liquid phase, in the presence of an inert-solvent and of a Raney nickel hydrogenation catalyst at a temperature of from about 25 to about C. and at a pressure of from about 500 to about 3000 pounds per square inch.

7. The process which comprises subjecting 5- nitro-3-cyclohexyl- 5 -methyltetrahydro-1,3-oxazine to the action of hydrogen underconditions of high temperature and pressure inthe presence of a reduced nickel catalyst and in the liquid phase, and recovering the resulting 2-amino-2- methyl-4-cyclohexyl 4 aza-l-pentanol thereby produced.

MURRAY SENKUS.

REFERENCES CITED The following references are of record in the OTHER, REFERENCES Pearson et al.: J. Am. Chem. 800., vol. 68, pp. 1225-1229, July 1946. 1 

1. AS NEW COMPOSITIONS OF MATTER, POLYAMINO ALCOHOLS HAVING THE FOLLOWING STRUCTURAL FORMULA: 